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(Modem 2 Sheets--Sheet 1.

P. M. MAHAN & S. R. OWEN. Machine for Extracting Gold from AuriferousDeposits. No. 233,632. Pate nted Oct. 26, I880.

WITNESSES IN VENTORS 3* ATTORNEY N. PETERS. PHOTO-LITNOGRAPNER.WASDHNG'TON. D C.

' 2 Sheets--Sheet '2. F. M. MAHAN & S. R. OWEN.

Machine for Extracting Gold from Auriferou-s Deposits No. 233,632.Patented Oct. 26., 1880.

(moueL) WlTNESSES v fiZMa ATTOR N EY NPETERS, PHOYG-LITHOGRAPugR.WASHINGTON. 07c.

NITE STATES PATENT Fries.

FRANK M. MAHAN AND SILAS R. OWEN, OF ST. JOSEPH, MISSOURI; SAID MAHANASSIGNOR OF ONE-THIRD TO DAVID BAILEY AND STOKELEY W. SLAYDEN; SAID OWENASSIGNOR TO SAID SLAYDEN.

MACHINE FOR EXTRACTING GOLD FROM AURIFEROUS DEPOSITS.

SPECIFICATION forming part of Letters Patent No. 233,632, dated October26, 1880,

Application filed May 17, 1880.

To all whom it may concern Be it known that we, FRANK M. MAHAN and SILASIt. OWEN, of St. Joseph, in the county of Buchanan and State ofMissouri, have invented a new and valuable Improvement in Machines forWVashing the Dirt of Auriferous Deposits and Extracting the Goldtherefrom; and we do hereby declare that the followingis a full, clear,and exact description of the construction and operation of the same,reference being had to the annexed drawings, making a part of thisspecification, and to the letters and figures of reference markedthereon.

This invention relates to improvements in machines for separating goldfrom aurii'erous deposits; and the novelty consists in the constructionand arrangement of parts, as will be more fully hereinafter set forth,and specifically pointed out in the claims.

In carrying out ourinvention we employ the device illustrated in theaccompanying drawings, which form a part of this specification, and inwhich Figure 1 represents a side elevation of our machine, partly insection; Fig. 2, a plan view. Fig. 3 is an end section; Fig. 4, a detailtrans verse section. Figs. 5 and 6 are details, and Fig. 7 a perspectiveof the shedding-plates.

In the accompanying drawings, A designates a tank that is kept nearlyfull of water. B is a long box, made of iron or other suitable material,having a curved bottom composed of grating covered over withscreen-wire. This screen is composed of sections of different degrees offineness, the finest being at the bottom, where the earth is thrown in,and the coarsest at the upper end thereof, each upper section beingcoarser than that next below. This box, when in position, is at an angleof about fifteen degrees to the horizon, and it is located in tank A.

A indicates an axle or shaft, having its bearings in the ends of saidbox and parallel to its bottom. This shaft projects through the lowerend of the box, and carries a sprocketwheel, by means of which it isrotated. It is provided from end to end with a single row of stirrers,a, set at short intervals in the form (Model.)

of a screw, which carries the tailin gs or refuse to the upper end ofthe box, whence they are discharged, the finer earth and precious metalsfalling through the screen into the bottom of the tank A. These grindersor stirrers are beveled in such form that they tend to assist the screwto carry the dirt up and to more 5 5 thoroughly mix and grind the same,and there are set in the said shaft as many straight grinders as may berequired inthe positions not interfering with the action of thescrew-grinder.

0 is a screw-conveyor arranged longitudinallyin the bottom of thetauk,for the purpose of conveying its contents, which is auriferousearth of the consistency of slush, to a set of elevators, D, working atits lower end in a well, E,into which the slush is discharged by 6 thescrew-elevator. The elevator D extends "ertically up a sufficientdistance and empties into a chute, G, which conducts the slush into anupright tank, H, having attached to opposite sides a series of amalgamplates, arranged at an incline, and forming with each other a zigzagpassage from top to bottom of said tank. At the bottom of tank H is awell provided with a series of pockets, as seen in Fig. 4, filled withmercury, which will arrest any coarse or 7 5 shot gold that may passdown over the amalgamated plates. From tank H the slush passes throughan outlet above the quicksilver-pocket into a tank, I, also providedwith amalgam plates.

K represents a valve or stop-cock, which can be adjusted in such amanner as to govern the outflow from the vertical tank H into thehorizontal tank I, and thus at will regulate the quantity of liquidslush within the tank H. It has been found that the best results will beobtained by keeping the tank H about twothirds full of the liquid slush,or such a quantity as will allow the compressed air to give sufficientagitation without forcing the slush over the top of the tank in itsupward progress. Thepassage-way for the slush through this tank isV-shaped in cross-section, and is in the form of a zigzag from side toside, as shown in Fig. 2. The walls of the zigzag passage 5 may also becovered with amalgamated plates from end to end, and the bottom of thetank is provided with pockets for the reception of quicksilver, so thatany gold passing through this chamber cannot fail to be arrested.

The tanks H I may be used together or separately, as convenience maydictate.

To facilitate the washing and perfect the separation of the auriferousfrom the earthy particles, we have applied in the tanks atmosphericpressure, with a view to agitating the slush, as follows: At rightangles to the tank I is a frame supporting a double-acting bellows orother blower. From the nozzle of this bellows or blower is anair-conduit, K, which passes along the top of tank I from end to end,connected to which are the tappipes K, arranged at an angle to pipe K,corresponding to the branches of the zigzag passage-way, one of saidpipes K being over each of said branches.

K designates distrilmting-pipes depending from pipes K and arranged atshort intervals. These pipes extend downward to near the bottom of thesaid angular passage-way, and they are bent toward the discharge end ofthe passage-way. When power is applied to the blower there is a constantvolume of air discharged in jets from pipes K, which agitates the slushand forces it toward the discharge end of said tank, and the commotionthus created forces every particle of the slush in contact with theamalgamated plates and quicksilver, to which the gold will adhere andthus be saved.

Atmospheric agitation is produced in the upright tank H by means of amain air-pipe, H, connected to the blower and extending down to a pointnear the bottom of said tank, where it is provided with adistributing-rose, H, perforated numerously on its under side, that itmay not become choked up with sand. The air forced by the blower throughthe rose rises to the top of the tank, and creates, in its zigzag coursethrough the labyrinthine passage form ed by the amalgamated plates, aViolent bubbling and agitation of the slush, thus greatly expediting thedeposition of gold-dust upon the said plates. From tank I the slush isdelivered into a well, L, at its educt end, from which the sediment isscooped up by the buckets of an elevator, M, and dropped upon an endlessapron, It. and conveyed to a suitable dum pin g-place. Theelevator-buckets have wire-gauze bottoms, through which the watertrickles back into the well L. This well, if water he scarce, or if, forother reasons, it be deemed requisite, may have an overflowpipedischarging into a suitable cistern or receptacle, whence it may bepumped and used again and again.

Motion is imparted to all the parts of the machine requiring motion froma line-shaft, S, by means of sprocket-wheels and endless chains, theformer being keyed upon the said shaft and on the journals of theworking parts aforesaid.

The following is the preferred arrangement:

1 is a sprocket-wheel on the journal of the screwshaft in box B, and 2 asimilar wheel on the line-shaft S, around which passes an endless chain.3 is a sprocket-wheel on the journal of conveyer O, and 4 is acorresponding one on the screw-shaft, around which an endless belt isalso passed. 5 and 6 are sprocket-wheels, respectively on the uppershaft of the elevator D and theline-shaft, and connected'by an endlessbelt. Thus the rotation of the line-shaft actuates the screw-grinder andconveyer, and through a crank, P, upon its end and a pitman, P, apuinp,0, which supplies the boX A with water. 7 is a sprocket-wheel on theupper sh aft of the elevator M, and 8 a similar wheel on the line-shaft,which are connected by an endless chain; and 9 and 10 are similar wheelson the shaft of the endless apron and line-shaft, respectively, whichare also connected byan endless chain. 11 and 13 are sprocket-wheelsupon a short shaft journaled in the frame above the bellows or blower,and connected,

respectively, with a sprocket-wheel, 12, on the line-shaft and a similarwheel, 14, upon the shaft or drum of the endless apron It. Thus all themoving parts of the machine derive motion from the line-shaft, whichderives power from a motor through suitable connections.

When a bellows is used to produce the airblasts it will have a centralpartition and a two-ported nozzle, one of said ports being appropriateto each division of the bellows, and each division having its own valve,so that while one division is expelling air through its port the otheris taking it in. Thus a constant and unfailing air-current is kept up,with no danger of back-suction through the nozzle, which sometimesoccurs in single-acting bellows.

.What we claim as new, and desire tosecure by Letters Patent, is-

1. In a machine for separating the gold from auriferous deposits, thetank A, havinga screwconveyer, O, in combination with the inclined box13, having a rounded gauze-covered bottom, and a longitudinal shaftcarrying the beveled grinding and stirring arms arranged in the form ofa screw-thread, and straight grinders, substantially as specified.

2. The elevator D, in combination with the wash-tank A, box B, providedwith the stirring-shaft, as described, conveyer 0, well E, and uprighttank H, provided with amalgamated plates forming a zigzag passage fromtop to bottom thereof, substantially as specified.

3. In a machine for extracting gold from auriferous deposits, the tankH, having a sys tem of amalgamated plates projecting inward fromopposite sides and inclining downward, in combination with the well E,the elevator D, having chute Gr, tank A, wash-box B, havin g ascreen-bottom, the elevating and stirring screw in said box, and thescrew-conveyer O, substantially as specified.

4. The combination, with tank H, having the recessed plates, arranged asshown, of the tank I, having the angular zigzag passage in its bottomextending alternately from side to side, substantially as specified. I

5. The tank I, having the zigzag passage of angular section lined orcovered with amalgamated plates, in combination with a well, L, at itseduct end, the elevator M, having gauze-covered buckets, and an endlessapron, R, substantially as set forth.

6. The tank I, having the zigzag inclined or V-shaped passage-wayprovided with amalgamated plates, in combination with pipe K and pipesK, provided with the distributingpipes K, substantially as described.

7. The tank I, having inclined zigzag passages, as described, incombination with the air-tube K, having tap-pipes K oblique thereto andcorresponding to the obliquity of the branches of the zigzag passage oftank I, and the distributing-pipes K, set at short intervals in saidpipe and discharging in the direction of the ednct end of the saidpassage, in combination with tank I and an air-forcing mechanism, asspecified.

8. The combination, with the tank H, provided with inclined amalgamatedplates, removable and recessed, as shown, and projecting from oppositesides and forming a zigzag passage-way from side to side from the top tothe bottom of said tank, of a blast-pipe discharging at the bottom ofthe tank under the last plate, whereby a violent bubblin g and agitationof the descending slush is created by the ascending air, as and for thepurpose set forth.

9. The tank H, having the removable recessed amalgamated plates,arranged at an incline and projecting alternately from opposite sides,in combination with the pipe H, extending outside of and close to thewall of said tank nearly to its bottom, curving inward, and provided atits end with a distributing-rose discharging downward, substantially asspecified.

10. The process of obtaining gold from auriferous deposits, consisting,in reducing the material to a fluid pulp, allowing such pulp to flowdownward, passing it in a tortuous course over amalgam plates, andsubjecting the vol ume of pulp in its downward course to currents ofcompressed air passing in an upward direction, for the purposespecified.

In testimony that we claim the above we have hereunto subscribed ournames in the presence of two witnesses.

FRANK M. MAHAN. SILAS R. OWEN.

Witnesses JAMES H. BORTLE, GEORGE H. ZIPH.

